1641664264278 has 32 divisors (see below), whose sum is σ = 3491646622560. Its totient is φ = 512782871040.

The previous prime is 1641664264241. The next prime is 1641664264283. The reversal of 1641664264278 is 8724624661461.

It is a super-2 number, since 2×1641664264278² (a number of 25 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (57) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 35118013 + ... + 35164728.

It is an arithmetic number, because the mean of its divisors is an integer number (109113956955).

Almost surely, 2^{1641664264278} is an apocalyptic number.

1641664264278 is an abundant number, since it is smaller than the sum of its proper divisors (1849982358282).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1641664264278 is a wasteful number, since it uses less digits than its factorization.

1641664264278 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70282992.

The product of its digits is 18579456, while the sum is 57.

The spelling of 1641664264278 in words is "one trillion, six hundred forty-one billion, six hundred sixty-four million, two hundred sixty-four thousand, two hundred seventy-eight".